MDF is fairly easy to get a clean cut with, but it's also prone to dull blades faster. I typically don't recommend going out to purchase a premium blade solely to cut MDF. A good bargain blade is often a good choice, but if you're only going to a cut a little bit of MDF, then a good blade is always nice to have for your more critical cuts in ply and hardwoods later on.
If you will be cutting quite a bit of MDF, a blade with a triple chip grind (TCG) will keep an edge better than most.
You don't mention whether you're looking for full kerf or thin kerf, but on the bargain end, the Oshlun line from Holbren, Amazon, or Eagle America is surprisingly good for the price. The Freud Avanti TK series is also a good value. The Freud LU82M010 is a good full kerf choice for MDF.
Last edited by knotscott; 05-31-2009 at 06:52 PM.